Journal of Earth Science & Climatic Change
Open Access

Abstract

Warm air rising from tropical areas descends in the 25 to 40o S latitudinal zone being further north in winter and south in summer. This descending arm of the Hadley Cell is associated with dry conditions and deserts around the southern hemisphere ? the Kalahari in southern Africa, the central Australian desert and the Atacama in Chile, South America. Global warming may be broadening the width of the zone?s high pressure cells thereby displacing low pressure systems further south. Some parts of the region have already experienced drier conditions which have affected water supplies, especially in south-western Australia where the ozone hole over Antarctica may be producing an additional effect. These regions are also growing very rapidly, partly because they all contain abundant mineral resources. The combination of drier conditions and growth is placing pressures on water supplies in countries within this zone. Transferring water from wetter areas to the north or south is very expensive and energy intensive as is desalination of seawater, both of which have been promoted as solutions to the growing water deficit. Both solutions contribute carbon dioxide emission and potentially will enhance global warming unless renewable sources of energy are used. The relative cost of these two solutions will increasingly depend on technological improvements. The talk will compare and contrast options across all three continents.

Biography

Dr. Don McFarlane gained his PhD in hydrogeology at the University of Western Australia in 1985. After a period in the state government where he managed state water policy and planning he took up a position in CSIRO to coordinate the Water for a Healthy Country Flagship in Western Australia. This paper reports work on four Sustainable Yield projects in Australia, work in the Copiapó River Basin in Chile and results reported by colleagues in Southern Africa. In 2004 he was awarded the CSIRO Chairman?s Medal for his contribution to the mapping and monitoring of dryland salinity and perennial vegetation.